SCR triac turn has turned in two directions, turn-off characteristics. Triac is essentially a two-way anti-parallel thyristor SCR BTA140, four PN semiconductor structure is formed by NPNPN five percent, three electrodes of semiconductor devices. Because the main electrode structure is symmetrical (both drawn from the N layer) SCR BTA412Y, so it's not a one-way thyristor electrode as an anode and a cathode, respectively, called SCR, but very similar to the control called The first electrode A1, the other is called the second electrode A2. The main disadvantage of the triac lower rate of increase in the ability to withstand voltage. This is because the triac is turned on end in one direction, in layers of silicon carrier has not returned to the off-state location, you must take appropriate protective measures. Triac control circuit elements are mainly used for communication, such as temperature control, lighting control, explosion-proof AC switch and DC motor speed and commutation circuit. Single SCR, triac discrimination: first one of the two test poles SCR BTA216, if the positive and negative test pointer not moving (R × 1 block), may be A, K or G, A pole (right way thyristor) may be T2, T1 or T2, G pole (for triac). If one has a measurement instructions for tens to hundreds of Europe, it certainly is way thyristor. And a red pen for the connected K-pole, black pen then for G pole, and the rest is the A pole. If the positive and negative test instructions are tens to hundreds of Europe, certainly for the triac. Then dial knob to R × 1 or R × 10 block retest, which must have a resistance slightly, slightly larger than a red pen is connected to G pole, black pen connects to T1 pole, the rest is extremely T2 . SCR SCR _ BTA204_ are fertile Electronics Dongguan City is provided by Wal-Electronic Technology Co., Ltd .. Dongguan City is Wal-Electronic Technology Co., Ltd. (www.dgmydz.com) (www.dgmydz.com) strong, credible, FET and other industries in Dongguan, Guangdong has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the electronics are fertile and you hand into the brilliant, for a better future! You can also access (www.dgmydz.com/supply_details_39267975.html), for more information about the company.